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European oak logs (Quercus robur, Quercus petraea) from the 15th auction of valuable logs in Slovenj Gradec in 2021 were included in the study. Of the 1,318 auctioned logs, 78 were randomly selected and visually graded into quality classes (A, B, C) according to the National Grading Rules (2017). In parallel, we analysed the wood growth dendrochronologically and the acoustic properties of the logs using the longitudinal vibration resonance method. The logs with the best quality had a larger diameter and, on average, wider annual rings. We confirmed the correlation between the visually determined quality and the obtained price of the logs. Longitudinal vibration velocity (v) and relative acoustic conversion efficiency (RACE) were positively correlated with log quality and price. The frequency spectra of the low-quality logs differed from the theoretical spectra. This study confirms the feasibility of non-destructive acoustic methods for evaluating oak log quality. V raziskavo smo vključili hrastovo hlodovino (Quercus robur, Quercus petraea) s 15. dražbe vrednejših sortimentov okroglega lesa v Slovenj Gradcu v letu 2021. Naključno smo izbrali 78 od 1318 licitiranih hlodov in jih skladno z veljavnim Pravilnikom o merjenju (2017) vizualno razvrstili po kakovosti (A, B, C). Vzporedno smo dendrokronološko analizirali priraščanje lesa ter z metodo frekvenčnega odziva pri vzdolžnem vzbujanju še akustične lastnosti hlodovine. Najkvalitetnejša hlodovina je bila večjih premerov, z več in povprečno širšimi branikami. Potrdili smo povezavo med vizualno določeno kakovostjo in doseženo ceno hlodovine. Hitrost vzdolžnega nihanja (v) in relativna učinkovitost akustične pretvorbe (RACE) sta bili s kakovostjo in ceno hlodovine pozitivno povezani. Frekvenčni spektri pri hlodovini nižje kakovosti odstopajo od teoretičnih. Raziskava je potrdila možnost uporabe nedestruktivnih akustičnih metod za oceno kakovosti hrastove hlodovine.

The work is part of the R&D&I Project PID2020-112954RA-I00 funded by MCIN/AEI/10.13039/501100011033. Publisher Copyright: © 2023 The Authors Fracture characterisation under mode I loading of Eucalyptus globulus Labill. bonded joints with one-component polyurethane adhesive (1C-PUR) is addressed in this work. The objective is to estimate the cohesive law representative of the fracture behaviour of these joints. A direct and two inverse procedures were employed to determine the softening laws. The direct method is based on local measurement of crack tip displacements using digital image correlation in the course of Double Cantilever Beam (DCB) tests, while the inverse methods rely on load–displacement data and on load-crack tip opening displacement relations by finite element modelling. It was verified that consistent results can be obtained from the three methodologies leading to the conclusion that the classical inverse procedure is the most appealing one owing to its simplicity. publishersversion published

This research deals with the processing of wood using a circular saw, which is associated with several risks and factors that affect the wood-splitting process. One of them is the wear of the teeth of the saw blade that change the magnitude of the cutting forces. The aim of this study is to compare real measured values and theoretical values when processing Norway spruce wood using two types of saw blades, i.e., sintered carbide (SC) and high-speed steel (HSS), with a diameter of 600 mm and 54 and 56 teeth, respectively. Experimental measurements were carried out on a special test device with the possibility of moving the tested wood into the cutting devices and a simple saw blade replacement system. The results of the contributions show significant differences, based on defined factors which represent the cutting and feed speed, which are supported by FEM analysis of cutting forces in the process of cutting wood—when changing the design of the saw blade. The results of the experiment show that the cutting conditions (cutting speed and feed speed) do not have a significant effect on the size of the cutting forces. The theoretical and real stress values for HSS discs ranged from 14 to 22 MPa. Significantly larger differences were recorded for discs with SC, where the real values of the maximum stresses were around 14 MPa and the theoretical ones around 25 MPa. When cutting spruce with a disc with SC slices, the maximum values of the theoretical cutting forces were in the range of 76 to 94 N and the maximum values of the measured cutting forces were in the range of 40 to 44 N.

The demand for construction timber is continuously increasing, due to its favourable characteristics. However, the adequate protection of wood is key to its successful use, as it is flammable and susceptible to biodegradation. Given that thermal modification enhances the durability of wood, and mineralisation with CaCO3 considerably improves its fire properties, it is worth considering the combined effects of the two methods. European beech (Fagus sylvatica) was selected to determine the effects of a) thermal modification, b) mineralisation through the in-situ formation of CaCO3, and c) a combination of the two procedures, on resistance to decay fungi, reaction to fire and the mechanical properties of the wood. Microscopic analysis and comparisons of the samples before and after exposure to fungi were also conducted. Mineralised wood generally had a slightly alkaline pH value and higher equilibrium moisture content, while thermal modification lowered the equilibrium moisture content. The present study demonstrated the combined effect of thermal modification and mineralisation: the best response to fire as well as resistance to fungi was achieved when the two treatments were combined. Results from the Brinell hardness and three-point bending tests indicate that both modification procedures can slightly impair the mechanical properties of the wood. Nasl. z nasl. zaslona. Opis vira z dne 6. 7. 2023. Bibliografija.

The importance of renewable and environmentally acceptable materials in the construction industry is increasing. Wood is one of the most important construction materials and its use in building applications has further expanded in recent decades, mainly due to the development of modern composites, firstly glue lam, OSB (Oriented Strand Board), LVL (Laminated Veneer Lumber) and a considerable breakthrough was later achieved with the development of cross-laminated timber. In order to enable even more extensive and reliable use of wood in outdoor applications, factors affecting a wood’s service life need to be understood. It is well known that fungal degradation of wood is predominantly affected by temperature and wood moisture content. In order to elucidate the influence of these two factors, long-term monitoring of temperature, relative humidity and moisture content at the newly-built Annex of the Department of Wood Science and Technology was carried out. The Annex is designed from CLT composites and glue-lam beams and was finished in December 2015. The results clearly show that microclimatic conditions in the monitored building in the first years of use are far below the limit required for fungal decay or mould growth.

To use wood as a structural element in vehicles, it is necessary to measure its physical properties locally in order to deduce its mechanical behaviour. Density is one of the characteristics that influences the most the mechanical properties, and it is on its measurement that this study will focus, using a technology that is still little studied for this application: terahertz radiation. Measurements using a Terahertz radar on samples will allow to obtain maps of the optical index and absorption coefficient, these values being linked to the density of the samples. The present study will consider wood species with various global densities and exhibiting local density pattern (growth rings) to assess the prediction of the density.

At present, the popularity of timber as a structural material is booming. However, the current knowledge on disproportionate collapse prevention and extreme loading of timber buildings is scarce. To prevent disproportionate and progressive collapse, catenary action is an important mechanism, where the axial capacity of bending members is activated. Because of the brittle behavior of timber in the relevant failure modes, it can only achieve catenary action via strengthening. In this paper, analytical expressions are derived for the elastic, plastic, and catenary capacity of laterally loaded wood and timber beams with a tension-side strip reinforcement. A load-path dependent M-N interaction diagram with damage accumulation explains the ultimate catenary capacity and the transition between the bending- and catenary-dominated load-carrying mode. The analytical expressions are validated and discussed based on tests on beech clearwood specimens reinforced with carbon fibers in a polyurethane matrix. Furthermore, a case study on glued laminated timber beams is presented to demonstrate the potential of reinforcing timber beams subjected to extreme loading., Construction and Building Materials, 385, ISSN:0950-0618

The fire reaction of various types of flammable lightweight materials is investigated using a cone calorimeter. The influences of parameters such as sample density, sample mass, effective heat of combustion and heat flux on the mass loss after exposition are discussed. Interpretations of the hemp fibers’ tests results lead us to propose a phenomenological model able to calculate the peak of heat release rate (pHRR) of such thermally thin materials, with or without flame retardant. A database gathering the whole results of tests performed on a large set of materials including fibers, bio-resources panels, bio-based concretes and fabrics is used to validate the proposed model. Interestingly, the model is found to be relevant also for denser wood specimens. The model is based on the distinction of the contributions of the exposed top layer and the deeper layer to the combustion. Indeed, in such materials, the heat conduction is limited (either by the intrinsic properties of the material or by the formation of an insulating char) and therefore the pHRR only depends on a limited volume of materials directly absorbing the heat flux from the radiant cone. Accuracy and limitations of the model are discussed.

Timber, as a building material, is subject to structural changes in the used interior, which result from the influence of various local environmental conditions and their changes during the service life. Samples of naturally aged historic silver fir (Abies alba Mill.) wood were taken from the roof of St. Barbara Church (Ravnik above Hotedršica, Slovenia). The slices of historic wood were dendrochronologically dated and analyzed by CIELab color determination, light microscopic analysis and IR spectroscopy. Our results showed that the interior of the 18th-century fir structural timber had lower color lightness (L*) and intensity (b*), particularly in the latewood. The partial increase in lignin and decrease in hemicelluloses relative to cellulose content, associated with an increased degree of crystallinity of cellulose, was confirmed by epifluorescence and polarized light microscopy combined with FTIR spectroscopy.

Timber, as a building material, is subject to structural changes in the used interior, which result from the influence of various local environmental conditions and their changes during the service life. Samples of naturally aged historic silver fir (Abies alba Mill.) wood were taken from the roof of St. Barbara Church (Ravnik above Hotedršica, Slovenia). The slices of historic wood were dendrochronologically dated and analyzed by CIELab color determination, light microscopic analysis and IR spectroscopy. Our results showed that the interior of the 18th-century fir structural timber had lower color lightness (L*) and intensity (b*), particularly in the latewood. The partial increase in lignin and decrease in hemicelluloses relative to cellulose content, associated with an increased degree of crystallinity of cellulose, was confirmed by epifluorescence and polarized light microscopy combined with FTIR spectroscopy.

International audience; The fire reaction of various types of flammable lightweight materials is investigated using a cone calorimeter. The influences of parameters such as sample density, sample mass, effective heat of combustion and heat flux on the mass loss after exposition are discussed. Interpretations of the hemp fibers’ tests results lead us to propose a phenomenological model able to calculate the peak of heat release rate (pHRR) of such thermally thin materials, with or without flame retardant. A database gathering the whole results of tests performed on a large set of materials including fibers, bio-resources panels, bio-based concretes and fabrics is used to validate the proposed model. Interestingly, the model is found to be relevant also for denser wood specimens. The model is based on the distinction of the contributions of the exposed top layer and the deeper layer to the combustion. Indeed, in such materials, the heat conduction is limited (either by the intrinsic properties of the material or by the formation of an insulating char) and therefore the pHRR only depends on a limited volume of materials directly absorbing the heat flux from the radiant cone. Accuracy and limitations of the model are discussed.

Wood fiber and its products are modified to increase fire and bio-resistance. The best results are achieved by using modifiers that enter into chemical interaction with the hydroxylated substrate, forming the organic matrix of the materials. The purpose of the research described in the article was to study the possibility of using boron-nitrogen compounds to modify cellulose and cellulose-containing materials to improve the performance, bio- and fire-protective properties of construction materials, as well as to optimize the consumption of boron-nitrogen compounds. As a result of the research, it was found that the boron-nitrogen compounds used in the compositions developed here chemically interact with hydroxyl groups at the C6-atom of cellulose. The chemical interaction of boron-nitrogen compounds with cellulose is an inter-crystalline process occurring without destruction of the crystal structure of the substrate since the modifier molecules bind with the more accessible hydroxyl groups of the amorphous regions of cellulose. Thus, surface modification with boron-nitrogen compounds does not result in accelerated aging of cellulose-containing materials and loss of strength but, on the contrary, increases the durability of wooden structures.

This is a data management plan for the DFG research project "Predictability of color changes of wood used indoor - A new approach to evaluate the color change as a function of the radiation dose". DFG Funding code / Project number: 442135169 Project website: https://gepris.dfg.de/gepris/projekt/442135169?language=en This data management plan (DMP) applies to the Research Data Management Organizer (RDMO) questionnaire and was operated with the RDMO software: https://rdmorganiser.github.io/en/, Grants: German Research Foundation (Deutsche Forschungsgemeinschaft (DFG) e.V.); Project number: 442135169

This is a data mamnagement plan for the DFG research project "Predictability of colour changes of wood used indoor - A new approach to evaluate the colour change as a function of the radiation dose". DFG Funding code / Project number: 442135169 Project website: https://gepris.dfg.de/gepris/projekt/442135169?language=en This data management plan applies to the RDMO (Research Data Management Organizer) questionnaire and was operated with the RDMO software: https://rdmorganiser.github.io/en/

The development of new materials for the construction sector is a global trend, and products that use by-products in their composition and have also incorporated technology are commercially competitive. Microparticles have large surface areas and can modify the microstructure of materials, positively affecting their physical and mechanical properties. In this context, this study aims to investigate the effect of incorporating aluminium oxide (Al2O3) microparticles on the physical and mechanical properties of oriented strand boards (OSBs) made from reforested residual balsa and castor oil polyurethane resin and to evaluate their durability performance under accelerated aging conditions. The OSBs were produced on a laboratory scale with a density of 650 kg/m3, strand-type particles measuring 90 × 25 × 1 mm3, using castor oil-based polyurethane resin (13%) and Al2O3 microparticle content ranging from 1% to 3% of the resin mass. The physical and mechanical properties of the OSBs were determined following the EN-300:2002 recommendations. The results obtained indicated that the OSBs with 2% Al2O3 presented thickness swelling significantly lower (at the 5% significance level) after being subjected to accelerated aging and internal bonding of the particles higher than the values obtained for the references, evidencing the positive effect of including Al2O3 microparticles in balsa OSBs.

Extractive activity is not limited to mining; it also occurs in the other forms of large-scale landscape destruction, including the deforestation involved in extensive infrastructure projects. Yet while resistance to activities such as fracking and coal mining has been intensively investigated within the extractivism debate under the collective term ‘contested extractivism’, resistance to the extraction of renewable parts of nature such as woodland has, by comparison, been somewhat neglected. Likewise, the academic debate has focused mostly on case studies from the global South. We argue that opposition to the felling of more than 85 hectares of woodland in the Forest of Dannenrod (Germany) for the construction of a highway is an example of contested extractivism in the global North. We portray the protest as a clash between extractivist and anti-extractivist notions in Europe, the latter partly transitioning into post-extractivist imaginaries. And although the area was felled in 2020, we argue that this opposition marked a turning point for the German environmental justice movement and sparked a national debate, despite persistent support mechanisms for wood extraction and negative media reports. L’activité extractive n’est pas limitée à l’exploitation minière ; elle se déroule aussi dans d’autres formes de destruction massive de l’environnement, dont la déforestation impliquée dans de vastes projets infrastructurels. Et pourtant, alors que la résistance aux activités tels la fracturation hydraulique et l’exploitation du charbon ont été intensivement investigués au sein du débat sur l’extractivisme sous l’égide de « l’extractivisme contesté », la résistance à l’extraction d’éléments renouvelables de la nature tel les bois a été comparativement quelque peu négligée. De même, le débat académique s’est focalisé principalement sur des études de cas du Sud global. Nous soutenons que l’opposition à l’abattage de plus de 85 hectares de bois dans la forêt du Dannenrod (Allemagne) pour la construction d’une autoroute est un exemple d’extractivisme contesté dans le Nord global. Nous considérons les manifestations comme affrontement entre notions extractifs et anti-extractifs en Europe, ce dernier transitionnant partiellement vers des imaginaires post-extractifs. Bien que la zone de forêt ait été abattue en 2020, nous soutenons que cette opposition a marqué un tournant pour le mouvement de justice environnemental allemand et a déclenché un débat national, malgré des mécanismes de soutien persistant en faveur de l’extraction de bois et des rapports médiatiques négatifs. El extractivismo no se limita a las actividades de minería; también está presente en otras formas de destrucción del paisaje a gran escala, incluyendo la deforestación provocada por grandes proyectos de infraestructura. Sin embargo, mientras que la resistencia a actividades como el fracking y la minería de carbón se ha investigado intensamente en el marco del debate sobre el extractivismo bajo el concepto de "extractivismo en disputa", la oposición frente a la extracción de elementos renovables de la naturaleza como los bosques ha sido escasa. Además, el debate académico se ha centrado principalmente en estudios de caso que tienen lugar en el Sur Global. En este capítulo señalamos que la oposición a la tala de más de 85 hectáreas del bosque de Dannenrod (Alemania) para la construcción de una autopista es un ejemplo de disputa contra el extractivismo en el Norte Global. Describimos las protestas contra este proyecto como una muestra del enfrentamiento entre ideas extractivistas y antiextractivistas en Europa. Estas últimas hacen parte de una transición parcial hacia imaginarios postextractivistas. Sostenemos que si bien la zona fue talada en 2020, las protestas contra el proyecto marcaron un punto de inflexión para el movimiento alemán por la justicia medioambiental, desencadenando un debate nacional a pesar de la persistencia de mecanismos de apoyo a la extracción de madera y del cubrimiento negativo de los medios de comunicación.

The construction sector has one of the most polluting economic activities. In this context, several policies are being launched by the European Union to promote the transition to a sustainable economy, and timber construction is a safe way to contribute to it. Due to the recent development of multistorey timber buildings, the architectural and structural typologies have not been widely studied yet and with not many studies from Southern Europe. In this context, the main objective of this research is to identify and analyse the trends in the use of wood as a structural material in multistorey timber buildings (≥4 floors) in the SUDOE region, i.e., Spain, Portugal, and Southwest France. The methodology involved identifying 28 timber buildings in the SUDOE region and 101 worldwide, most of them in Europe, and sending online information request forms to different actors involved in their design and construction, collecting plans and BIM models, and performing technical study visits to the identified reference buildings. The collected information was included in open-access technical datasheets, and different indicators in terms of building uses, structural system, wood species, and wood volume, among others, were defined. The results showed that there is a tendency to construct taller timber buildings in the SUDOE region with a predominant use of local softwood species, with ratios of wood volume per built area varying between 0.3 and 0.4 m3/m2. The mass timber typology using cross-laminated timber (CLT) is mainly used for residential buildings, while post and beam are used for educational and offices buildings. In addition, a potential embodied CO2 equivalent depending on the building typology and use was also analysed.

The use of energy-saving materials is an effective strategy for decreasing energy consumption and carbon emission. Wood is a type of biomass material with a natural hierarchical structure, which results in its high thermal insulation. It has been widely used in construction. However, developing wood-based materials without flammability and dimensional instability is still a challenge. Herein, we developed a wood/polyimide composite aerogel with a well-preserved hierarchical pore structure and dense hydrogen bonds inside, resulting in its excellent chemical compatibility and strong interfacial interactions between its two components. This novel wood-based composite was fabricated by removing most hemicellulose and lignin from natural wood, followed by the fast impregnation using an ‘in situ gel’ process. The introduction of polyimide into delignified wood substantially improved its mechanical properties, with the compression resistance being improved by over five times. Notably, the thermal conductivity coefficient of the developed composite was approximately half that of natural wood. Furthermore, the composite exhibited excellent fire-retardancy, hydrophobicity, thermal insulation, and mechanical properties. This study provides a novel method for wood modification, which not only aids interfacial compatibility between wood and polyimide but also retains the properties of the two components. The developed composite can effectively reduce energy consumption, making it promising for practical and complex thermal insulation applications.

In this paper, we address reducing material consumption, conscious material selection, taking advantage of upcycling opportunities, and considering the reuse of components after the structure’s end-of-life in the context of ephemerality. We observe the realized Zero Gravity Pavilion through the lens of (dis-)assembly and (re-)use. The pavilion is presented as a showcase for the responsible design of lightweight structures, in which the geometry of the overall structure and all its components serves as a mediator between the specific material properties and the specific structural requirements of a kinematic structure, and simultaneously enhances both functionality and its spatial effects. The pavilion is a light, kinematic structure and architectural space, which has been assembled, disassembled and reassembled several times in different locations, where it has been continuously modified and adapted. Thus, ease of assembly and rapid disassembly, as well as reuse of components, presented challenges from the beginning of the design process but also triggered ultimately simple solutions in detailing and fabrication. The entire structure is designed so that all components can be easily separated from each other. The paper analyzes and describes in retrospect how much of the material was processed from raw material, how much of them was (re-)used for the construction of the structure and how much of them could be reused after the final disassembly. Based on the total weight, 96% of the pavilion has been seen as reusable after all cycles of its use and its final disassembly. The presented study is considered a step towards a new perception of architectural aesthetics that reflects the responsible use of materials and prioritizes the question of how long structures should last to better shape our future built environment.

Biomass materials play a key role in the renewable energy market as they can serve as a suitable alternative to fossil fuels. However, the quality of the material entering bioenergy plants is often a cause of technical concern. Biomass quality assessment is crucial not only for energy characterization but also for environmental and operational aspects. The goal of this study is to characterize and classify the biomasses used by Italian power plants with reference to the quality classes stated by the ISO standard 17225:2021. A further objective is to verify the ability of the standard to classify heterogeneous and specific biomasses. In this study, more than 900 biomass samples were analyzed. The samples were collected from several Italian power plants with >5 MWe between 2010 and 2020, and the most important physical and chemical parameters were analyzed according to the international standards of reference. The results of the analyses were collected in a large dataset used for subsequent statistical analyses. Statistical analyses applied are Principal Component Analysis and Pearson correlation maps, which showed that the ash content is a fundamental and ideal parameter to assess the biomass quality. Results obtained demonstrate that herbaceous biomasses are of low quality mainly due to the high ash content; a relatively low ash content was found for woody biomasses.

This webinar presented the state-of-the-art of digitalisation in wood construction and architecture and how digital tools and Industry 4.0 allow to better integrate the whole process from design, planning, pre-fabrication and construction.

This study proposes the use of genetic analysis as a complementary method for species identification in the genus Pinus, particularly in cases where anatomical identification is challenging. Pinus species were grouped based on anatomical similarities, and the efficacy of using ycf1b, which is the most variable for Pinus species identification, and rbcL, which is a suggested DNA barcode for land plants, was evaluated within each group. Sequences for each species were obtained from the National Center for Biotechnology Information database and were used to perform phylogenetic analysis. Among the species in Group 1 (P. echinata, P. elliottii, P. ponderosa, P. radiata, P. rigida, P. taeda, and P. virginiana), rbcL was only effective in identifying P. radiata and P. ponderosa, while ycf1b classified five species. An additional DNA barcode, trnH-psbA, was needed to identify P. radiata and P. taeda. In Group 2 (P. densiflora, P. sylvestris, and P. thunbergii), most species were identified using both rbcL and ycf1b, with the exception of possible hybrids of P. densiflora and P. sylvestris. In Group 3 (P. koraiensis and P. strobus), two species were identified using rbcL and ycf1b. Combining genetic species identification with anatomical identification can accurately identify species of the genus Pinus.

Almost 200 nations, including the European Union, have signed the Paris Agreement that aims to limit the temperature rise to 1.5 °C above pre-industrial levels by reducing greenhouse gas (GHG) emissions. To meet this target, a significant decrease in GHG emissions by 2030 and net zero by 2050 is necessary. To determine the role of wood products in achieving a 55% reduction in GHG emissions by 2030 compared with 1990 levels, we investigated Slovenia’s potential, which has close to 60% forested areas. Therefore, the country could use wood-based products to achieve the agreed-upon climate goals. Nevertheless, uncertainties remain regarding the extent to which increased tree harvesting, local manufacturing, and the utilization of wood products can aid in substituting fossil-derived materials and reducing GHG emissions. A new model was constructed to increase the understanding of the wood products’ (throughout the forest-based industrial ecosystem, incl. construction) potential contribution to reaching the stated emissions targets. Using this linear programming (LP) mathematical optimisation model and carbon footprint calculations based on life cycle assessment methods, a wood flow distribution, the financial investment needed to process these quantities, and the GHG emissions produced and/or saved were calculated. The findings stipulated that Slovenia has the potential to achieve 55 % less GHG emissions by 2030 by expanding logging to at least 3 million m3 and converting the timber to a larger amount of long service-life wooden items made (and utilised) within the country. Such products accumulate carbon for a long time and decrease the need for materials that cause higher GHG emissions. Concomitantly, a better appreciation of the substitution effects in official carbon accounting would be needed. Moreover, to materialize the potential decrease in emissions would require Slovenia’s construction sector to replace fossil- and mineral-based materials with lignocellulosic products, and to increase the capacity to utilize lower-quality wood in high added value applications, which would require significant investment. This paper offers a comprehensive analysis of diverse optimisation outcomes obtained from the investigation into climate action through the use of wood products in Slovenia.

Almost 200 nations, including the European Union, have signed the Paris Agreement that aims to limit the temperature rise to 1.5 °C above pre-industrial levels by reducing greenhouse gas (GHG) emissions. To meet this target, a significant decrease in GHG emissions by 2030 and net zero by 2050 is necessary. To determine the role of wood products in achieving a 55% reduction in GHG emissions by 2030 compared with 1990 levels, we investigated Slovenia’s potential, which has close to 60% forested areas. Therefore, the country could use wood-based products to achieve the agreed-upon climate goals. Nevertheless, uncertainties remain regarding the extent to which increased tree harvesting, local manufacturing, and the utilization of wood products can aid in substituting fossil-derived materials and reducing GHG emissions. A new model was constructed to increase the understanding of the wood products’ (throughout the forest-based industrial ecosystem, incl. construction) potential contribution to reaching the stated emissions targets. Using this linear programming (LP) mathematical optimisation model and carbon footprint calculations based on life cycle assessment methods, a wood flow distribution, the financial investment needed to process these quantities, and the GHG emissions produced and/or saved were calculated. The findings stipulated that Slovenia has the potential to achieve 55 % less GHG emissions by 2030 by expanding logging to at least 3 million m3and converting the timber to a larger amount of long service-life wooden items made (and utilised) within the country. Such products accumulate carbon for a long time and decrease the need for materials that cause higher GHG emissions. Concomitantly, a better appreciation of the substitution effects in official carbon accounting would be needed. Moreover, to materialize the potential decrease in emissions would require Slovenia’s construction sector to replace fossil- and mineral-based materials with lignocellulosic products, and to increase the capacity to utilize lower-quality wood in high added value applications, which would require significant investment. This paper offers a comprehensive analysis of diverse optimisation outcomes obtained from the investigation into climate action through the use of wood products in Slovenia.

Aquest treball estudia els avantatges i inconvenients del mur cortina de fusta davant la resta de sistemes habituals de mur cortina del mercat europeu. Per això, es centra en l'estudi dels materials que el formen i les seves característiques i el consum de recursos que suposen al llarg de tota la vida útil. El presente trabajo estudia las ventajas e inconvenientes del muro cortina de madera frente al resto de sistemas habituales de muro cortina del mercado europeo. Para ello se centra en el estudio de los materiales que lo forman y sus características y el consumo de recursos que suponen a lo largo de toda su vida útil. This project studies the advantages and disadvantages of the wooden curtain wall compared to other common curtain wall systems on the European market. For this purpose, it focuses on the study of the materials used, their characteristics and the consumption of resources throughout their useful life.

The goal of this study is to find out how some properties of wood–polymer nanocomposites are affected by the processing technology, the nanomaterials, and the ratio of coupling agents. To achieve this objective, the extruded and dry blended samples are made from wood flour with MAPP, ZnO nanoparticles (0, 1, 3, and 5 wt%), and polypropylene. The mechanical properties of the nanocomposites improve significantly with ZnO and MAPP loading. Due to the more homogeneous structure of nanocomposites, better mechanical results are obtained with the extrusion method. With ZnO and MAPP loading, the thermal stability of nanocomposites improves. The storage and loss modulus values indicate that the processing technology of nanocomposites could be a key factor in the resistance of the materials obtained by extrusion. The storage and loss modulus of nanocomposites manufactured by the extrusion technology are determined to be higher than those of the samples produced using the dry blending method.

Listeria monocytogenes is a significant concern in cheese production. It has been assumed by some that wood surfaces pose a greater risk for pathogen contamination during cheese production. The goal of this study was to evaluate the effect of the microbiota obtained from wooden boards used in cheese ripening on the growth of Listeria monocytogenes. Bacterial communities from the surface of wooden boards obtained from cheese-ripening facilities were inoculated into tryptic soy broth (TSB) and incubated at 11 °C for 48 h. These communities (108 CFU/mL stationary phase cells) were co-incubated with 104–105 CFU/mL L. monocytogenes 2203 at 11 °C for up to eight days. At various times, samples were removed, diluted in sterile saline and plated on modified Oxford agar. Bacterial communities from each of the five boards from three different facilities significantly inhibited growth of L. monocytogenes in vitro, compared to growth of L. monocytogenes 2203 alone. Using 16S rRNA analysis, we identified sequences belonging to the genera Carnobacterium, Leuconostoc and Staphylococcus as the most abundant in the communities grown in TSB. Leuconostoc mesenteroides and Staphylococcus equorum isolated from the most inhibitory community significantly inhibited growth of L. monocytogenes in TSB at 11 °C, compared to growth of L. monocytogenes 2203 alone. These findings suggest that some members of the complex microbial communities on wooden boards in cheese aging facilities might inhibit the growth of L. monocytogenes.

Dimensioning adhesively bonded joints remains a challenging task. Their diversity in geometry and material (including combinations thereof), characteristic stress peaks, scatter and brittleness are aspects few practitioners are prepared to handle for dimensioning purposes. As developed in the first part of this two-part paper, direct stress based methods, despite diverse fudging techniques, proved to be unsuitable. This left the field open for fracture mechanics, which, however, departed very much from the engineering reality leading to only lukewarm acceptance from practitioners. Almost unnoticed, probabilistic methods, much closer to classical mechanics, may offer an alternative. Based upon the presentation, in the first part of this series, of the concepts, the authors suggested an implementation in terms of design procedure. The second part of this two-part paper, is dedicated to the presentation of several examples, from available literature, of adhesively bonded joints involving a large variety of typologies (single and double-lap, tubular, and hybrid joints) and materials (fibre-reinforced polymers, steel, wood). The focus therein is set on practitioner oriented aspects, in particular on techniques for implementation.

The aim of this thesis is to investigate biomaterials using one and two-dimension Laplace Nuclear Magnetic Resonance (LNMR). LNMR is a class of NMR experiments that cover relaxation and self-diffusion measurements. Multidimensional LNMR experiments improve resolution and enable correlating relaxation and diffusion parameters. However, multidimensional experiments are limited by their long experiment times. To overcome this issue, acceleration methods can be used, such as ultrafast Laplace NMR (UF LNMR), which allows for measuring two-dimension data in a single scan. The first part of the thesis focuses on investigating the pore structures of cellulose nanofibril (CNF) aerogels using NMR cryoporometry, diffusometry, and magnetic resonance imaging (MRI). Aerogels are a special kind of material which have low density and high surface area. CNF aerogels are environmentally friendly and utilized as oil and chemical spill sorbents. The NMR methods allowed us to determine the nano-, micro- and submillimeter scale pore size distributions of CNF aerogels. The second part of the thesis concentrates on accelerating restricted diffusion measurements. Two different accelerating strategies were used. In the ultrafast approach, various effective gradient pulse lengths are encoded into a layer of the sample in a single scan. In the time-resolved approach, random increments of gradient strengths are associated with a constant increase in diffusion delay. Both methods were shown to be able to measure the restricted diffusion of water molecules inside a thermally modified wood sample with a ten-fold decreased experiment time. The third part of the thesis focuses on evaluating the changes in cheese structure during ripening using a single-sided NMR magnet. The cheese structure was monitored using one- and two-dimensional T2, T1-T2, and D-T2 NMR experiments. The experiments enabled observation of the three main components of cheese, namely water, fat, and water associated with casein protein as well as monitoring their evolution as a function of ripening time. In the last part of the thesis, we demonstrate that ultrafast diffusion exchange spectroscopy (UF DEXSY) experiments are feasible by a single-sided NMR magnet. Significant sensitivity boost provided by dissolution dynamic nuclear polarization (dDNP) method enabled single-scan UF DEXSY measurements in a fraction of a second. We exploited the method in the investigation of water exchange between intra- and extracellular pools in fresh yeast cells.

Wood, as a naturally green and environmentally friendly material, has been widely used in the construction and decoration industries. However, the flammability of wood poses serious safety problems. To improve the fire resistance of wood, In this study, it is proposed to use calcium chloride (CaCl2) and disodium hydrogen phosphate (Na2HPO4, DSP) to impregnate wood for multiple cycles. The experimental results show that phosphate mineral precipitation can be deposited on the surface of the wood. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) are used to analyze the micromorphology of mineral precipitation and use the MIP test to analyze the treated wood pore structure. The results show that with the increase in the number of cycles, the phosphate deposited on the surface of the wood increases, and the cumulative pore volume and water absorption rate of the wood after 10 cycles are 54.3% and 13.75% lower than that of untreated wood respectively. In addition, the cone calorimeter (CONE) confirmed that the total heat release (THR) and total smoke production (TSP) of wood treated in 10 cycles have decreased by 48.7% and 54.2% respectively compared with the untreated wood. Hence, this treatment method not only improves the mechanical properties of wood. It also improves fire resistance.

To date, the share of research, teaching materials, and practices related to the use of timber in bridge projects in Finland are quite limited compared to other materials, such as concrete. This article, which also includes a structural design example for dimensioning a girder bridge, focuses on the status, applications and prospects of wood use in bridge construction, reflecting the Finnish professionals’ point of view. Key findings highlighted that: (1) the ideal use of wood would be in private road bridges and light traffic bridges; (2) while the use of wood in the bridge was assessed to be advantageous in terms of ecology, aesthetics, and environmental friendliness, it was reported to be disadvantageous in terms of long-term durability and connection details; (3) concrete and steel, whose prices fluctuate, could gradually be replaced by wood, a renewable material; (4) timber-concrete composite bridges were expected to become widespread in the future; (5) cross-laminated timber (CLT) could open up an opportunity for bridge decks; and (6) service limit state is often decisive for the dimensioning of wooden bridges. It is recommended to implement large-scale public projects for the wooden bridges by creating sustainable business models that will be supported both legitimately and economically by the local government. In this sense, close cooperation between authorities and other key market stakeholders is crucial.

To enhance the stability of wood and decrease restrictions on its use in the furniture industry, hydrophobic modification can be employed to confer waterproof, anti-fouling, and self-cleaning properties. The present study outlines the preparation of silica sol using the sol–gel method, followed by impregnation and chemical vapor deposition methods to modify the sol. After grafting 1H,1H,2H,2H-perfluoro-decyl trichlorosilane (FDTS), hydrophobic and superhydrophobic properties were imparted to the wood substrate. To explore the correlation between the surface properties of the wood substrate and superhydrophobic coatings, the densities, porosities, and surface roughness of various tree species were compared. The results showed that the sol–gel method successfully constructed hydrophobic coatings on different wood substrates, with six samples (poplar, elm, toon wood, paulownia, ashtree, and black walnut) achieving superhydrophobic surfaces, with densities ranging from 0.386 to 0.794 g/cm3, porosity ranging from 13.66 to 42.36%, roughness ranging from 4.660 to 11.244 um, and maximum water contact angle of 165.2°. Whereas beech and rosewood only reach the hydrophobic surface. Although the coatings demonstrated good resistance to water, pollutants, self-cleaning, and chemical agents, further improvements are necessary to enhance mechanical wear resistance.

Objectives The aim was to identify, appraise, and synthesize the scientific evidence of the relationship between potential occupational sensitizing exposures and the development of asthma based on systematic reviews. Methods The study was conducted as an overview of systematic reviews. A systematic literature search was conducted for systematic reviews published up to 9 February 2020. Eligibility study criteria included persons in or above the working age, potential occupational sensitizing exposures, and outcomes defined as asthma. Potential occupational sensitizing exposures were divided into 23 main groups comprising both subgroups and specific exposures. Two reviewers independently selected studies, extracted study data, assessed study quality, and evaluated confidence in study results and level of evidence of the relationship between potential occupational sensitizing exposures and asthma. Results Twenty-seven systematic reviews were included covering 1242 studies and 486 potential occupational sensitizing exposures. Overall confidence in study results was rated high in three systematic reviews, moderate in seven reviews, and low in 17 reviews. Strong evidence for the main group of wood dusts and moderate evidence for main groups of mites and fish was found. For subgroups/specific exposures, strong evidence was found for toluene diisocyanates, Aspergillus, Cladosporium, Penicillium, and work tasks involving exposure to laboratory animals, whereas moderate evidence was found for 52 subgroups/specific exposures. Conclusions This overview identified hundreds of potential occupational sensitizing exposures suspected to cause asthma and evaluated the level of evidence for each exposure. Strong evidence was found for wood dust in general and for toluene diisocyanates, Aspergillus, Cladosporium, Penicillium, and work tasks involving exposure to laboratory animals.

The texture and color on wood are key factors that influence an individual's perception of it. However, little research has been done to confirm what kind of pattern in textures and colors are more likely to evoke individual aesthetic pleasure. Therefore, twenty-four decorative wood from northern China were selected, identified, and quantified in their colors with a CR-5 Colorimeter. We picked out eight kinds of wood with optimal texture characteristics through feature-fusion wood grain recognition (FWGR) and enhanced the texture features with photoshop in VR space. The result show that, in the color dimension, woods in the hue range of 20-25 and saturation of 65-75 were considered beautiful for individual perception of aesthetic. In the texture dimension, the size of the space affects the individual's preference for texture. When the pattern of the wood ray is continuous and clear, the individual's perception of its fluidity is enhanced; while for the fuzzy and interrupted pattern of the wood ray, the individual does not follow the fluidity of the line but focuses on the overall uniformity.

The impregnation of elements made of wood is one of the most important stages of their maintenance and the modification of their parameters. Incorrectly prepared material is sensitive to moisture, fungi, algae or weather conditions. In the case of large wooden elements or ready-made installations, impregnation is often performed not indoors, but outdoors. Despite the obvious advantages, this solution also has a number of disadvantages. One of them is the long duration of the impregnation process, as well as the variability in the process parameters along with changing weather conditions. In addition, the final material properties may differ not only from batch to batch, but also within the batch. In order to eliminate these problems, the equipment for wood impregnation was modernized. As part of the work, models of installation elements were made, a computer simulation was performed, and the necessary design calculations were carried out. The work will be crowned with the practical implementation of the proposed solutions in test equipment and the verification of design assumptions. The effect of the modernization of the system was a significant shortening of the impregnation process, as well the ability to obtain a final product of higher quality.

Flame treatment is an ancient technique for surface protection of wood. Further processing of charred wood elements depends on aesthetic and protective requirements. This study presents some general properties and weathering behaviour of the Norway spruce (Picea abies (L.) Karst.) and the European larch (Larix decidua Mill.), protected by variations of sanding, charring, charring + brushing, and coating treatments. Charring and charring + brushing reduced the original mass of the samples by up to 8% and notably changed their colour (ΔE* ≤ 75). A study of chemical properties showed that charring dehydrated the wood and degraded lignin and hemicelluloses. The surface roughness of the wood after charring and charring + brushing increased by as much as 560%, while coating with waterborne acrylic high build stain had no effect on the roughness of these surfaces. The type of surface treatment of the wood did not affect the uptake of the coating in the wood samples, but the uncoated and coated spruce wood absorbed more water than larch wood. Higher water absorption was observed in the samples treated by charring, and it decreased when the char layer was removed by brushing. The film of a waterborne high build stain reduced water uptake only for surfaces treated by sanding and charring + brushing. Larch wood exhibited higher surface hardness (EHz ≤ 1.70 MPa) than spruce wood (EHz ≤ 0.89 MPa), with the brittle char layer reducing the determined hardness of the tested surfaces. During two years of natural weathering, the char layer was removed from the wood surface, even if the samples were additionally coated. The greatest colour changes during weathering were observed on samples treated by sanding (ΔE* ≤ 60) and sanding + coating (ΔE* ≤ 33), followed by samples treated with charring + brushing (ΔE* ≤ 10) and samples treated with charring (ΔE* ≤ 9). In summary, treating wood by charring in combination with brushing was the best wood protection technique.

This experiment compared commercially available moisture meters (three capacitive metersand one resistance meter) and tested their predictive ability at different moisture conditions on selected beech (Fagus sylvatica) and spruce (Picea abies (L.) Karst.) wood samples. The measurements were carried out on the samples at specified moisture intervals ranging from 5% to 30% moisture content (MC). The resistance meter showed a close correlation to gravimetric MC values; the influence of the measuring direction for MC below 17% was found when higher MCs in the transverse direction for both species were archieved. The difference was 4.6 times higher for softwood and 1.6 times higher for hardwood. Differences between radial and tangential transverse measuring were not observed. The close correlation coefficient of MC measurements was also found for capacitive methods. The effect of the direction was found for all the tested meters when higher MC values in the longitudinal measurements were found. This effect was especially significant at an MC of wood higher than 20 wt.%. For two capacitive methods, the effect of annual ring deflection only in the spruce samples was found where higher MC values in the tangential direction were observed.

Various water treatment processes make extensive use of porous polymeric membranes. A key objective in membrane fabrication is to improve membrane selectivity without sacrificing other properties such as permeability. Herein, LiCl (0–2 wt.%) was utilised as a preforming agent in fabricating biomass-derived cellulosic membranes. The fabricated membranes were characterised by dope solution viscosity, surface and cross-sectional morphology, pure water flux, relative molecular mass cut-off (MWCO, 35 kDa), membrane chemistry, and hydrophilicity. The results demonstrated that at the optimum LiCl concentration (0.4 wt.%), there is an interplay of thermodynamic instability and kinetic effects during membrane formation, wherein the membrane morphology and hydrophilicity can be preferably altered and thus lead to the formation of the membrane with better rejection at no detriment to its permeability. Publishers version

Financiaciado para publicación en acceso aberto: Universidade de Vigo/CISUG Microwave-assisted autohydrolysis is an environmentally friendly intensification technology that permits the selective solubilization of hemicelluloses in form of oligosaccharides in a short time and with low energy consumption. The purpose of this work was to evaluate the suitability of microwave-assisted autohydrolysis to produce oligosaccharides and phenolics with potential prebiotic and antioxidant activities from Robinia pseudoacacia wood. The influence of treatment time (0–30 min) and temperature (200–230 ◦C) on oligosaccharide production was studied and conditions of 230 ◦C and 0.25 min resulted in maximum content of xylooligosaccharides (7.69 g XO/L) and more efficient energy consumption. Furthermore, under those conditions, liquors showed high contents of phenols (80.28 mg GAE/g of RW) and flavonoids (44.51 RE/g) with significant antioxidant activities (112.07 and 102.30 mg TE/g, measured by ABTS and FRAP tests, respectively). Additionally, the solubilized hemicelluloses were structurally characterized by HPAEC-PAD, MALDI-TOF-MS, FTIR and TGA/DSC, and HPLC-ESI-MS analysis allowed the tentative identification of 17 phytochemicals. Ministerio de Economía y Competitividad | Ref. PID2019-110031RB-I00 Xunta de Galicia | Ref. ED431C 2017/62-GRC Ministerio de Ciencia e Innovación | Ref. FPU21/02446 Ministerio de Ciencia e Innovación | Ref. PRE 2020 093359 Ministerio de Ciencia e Innovación | Ref. RYC2018-026177-I Xunta de Galicia | Ref. ED481B-2022-020

In this study, we synthesized and characterized a 3D network of silver nanowires (AgNWs), employing the polyol approach in ethylene glycol (EG) as the reductant and polyvinylpyrrolidone (PVP) as the structure-directing agent for the growth of AgNWs to design inexpensive, timely responsive AgNWs-based heaters with different substrates. Data obtained from a field emission scanning electron microscope (FESEM) revealed that the average diameter of the synthesized AgNWs was 22 nm, and the average length was 28 µm. UV-visible absorption spectroscopy showed that AgNWs developed in a very pure phase. We investigated the impact of substrate type on the heating dissipation performance by depositing AgNW thin film over three chosen substrates made from readily available materials. The findings indicated that the AgNW-based heater with the wood substrate had the lowest response time of 21 s, the highest thermal resistance of 352.59 °C·cm2/W, and a steady temperature of 135 °C at a low bias voltage of 5 V compared to cement (95 s, 297.77 °C·cm2/W, and 120 °C) and glass (120 s, 270.25 °C·cm2/W, and 110 °C).

Natural wood with oriented microchannels and unique multi-level structures is an ideal candidate for making water treatment membranes. Here, palladium nanoparticles are loaded into different kinds of natural woods and the degradation property of the wood membranes for organic pollutants are investigated. The water flux of hardwoods is significantly higher than that of softwood due to the existence of large vessel elements. For the single pollutant, both hardwood and softwood show high degradation efficiency for methylene blue and methylene orange, while the degradation efficiency of the softwoods for 4-nitrophenol is significantly higher than that of the hardwoods due to their lower water flux. For the mixed pollutants, all the wood membranes have a good degradation property for different concentrations of methylene blue in polluted water, while the degradation efficiency of high concentration methylene orange and 4-nitrophenol is low. Our work will provide some guidance for the degradation of organic pollutants in actual polluted water.

Brazil has advanced in export volume but has not been able to increase prices over the last decade for wood products. This work seeks to contribute to the understanding of this conflicting scenario, evaluating the growth in the revenue of Brazilian exports of these products during two periods: 2011-2015 and 2016-2020, as well as decomposing its effects in price, exchange rate, and volume. The method applied was the shift-share, widely used to identify determinants of sectoral and regional economic growth, being a precursor to the approach in the analysis of forest sector exports. Historical series for 5 (five) categories of wood products were analyzed, with export data from the Ministry of Economy. The historical series of nominal exchange rates from the Institute of Applied Economic Research (IPEA) was used. The real effective exchange rate (RER) followed the methodological note of the IPEA. All product categories analyzed had positive effects in terms of volume, for both periods, with a greater proportion in the second being driven by the exchange rate, although with a loss in real price, failing to offset inflation. The only exception was wood manufacturers, a product with higher added value, which presented gains in volume, exchange rates, and price. The volume effect was the most relevant, followed by the exchange rate as a result of the appreciation of the dollar against the real against the exchange rate and control of inflation in terms of the divergent effects on the national and international scenario. The price presented negative variations in export revenue, with a decline over the period. In addition to the added value of exported products, world stocks and levels of consumption may have contributed negatively to this scenario, affecting all categories of exported products, except for manufactured wood products, the only category that did not reflect such justifications. RESUMO O Brasil avançou em volume de exportação, mas não conseguiu aumentar preços ao longo da última década para os produtos de madeira. Este trabalho busca contribuir com o entendimento deste cenário destoante, avaliando o crescimento na receita das exportações brasileiras desses produtos durante dois períodos: 2011-2015 e 2016-2020, bem como, decompondo seus efeitos em preço, câmbio e volume. O método aplicado foi o shift-share, amplamente utilizado para identificar determinantes do crescimento econômico setorial e regional, sendo precursora a abordagem em análise de exportações do setor florestal. Foram analisadas séries históricas para 5 (cinco) categorias de produtos de madeira, com dados de exportação do Ministério da Economia. Utilizou-se a série histórica de taxa de câmbio nominal do Instituto de Pesquisa Econômica Aplicada (IPEA). A taxa de câmbio efetiva real (TCR) seguiu a nota metodológica do IPEA. Todas as categorias de produtos analisadas apresentaram efeitos positivos em volume, para ambos os períodos, com maior proporção no segundo, sendo impulsionado pelo câmbio muito embora com perda em preço real, não conseguindo compensar a inflação. A única exceção foi com manufaturas de madeira, produto de maior valor agregado, que apresentou ganhos em volume, câmbio e preço. O efeito volume foi o mais relevante, em seguida o câmbio como reflexo da valorização do dólar frente ao real em face da taxa de câmbio e controle de inflação em termos dos efeitos divergentes no cenário nacional e internacional. O preço apresentou variações negativas na receita de exportação com queda ao longo do período. Além de valor agregado dos produtos exportados, estoques mundiais e níveis de consumo podem ter contribuído negativamente com este cenário, afetando todas as categorias de produtos exportados, exceto produtos manufaturados de madeira, única categoria que não refletiu tais justificativas.

The use of disinfection and cleaning chemicals in several municipal facilities, such as swimming pools and drinking water treatment plants, causes the degradation of various types of wood, which leads to failures in equipment and the corresponding need for maintenance. This degradation creates added costs for municipalities, as well as the closure of certain facilities due to curative or preventive maintenance and, in many cases, public health issues, due to the water being contaminated with deteriorating products. Through a thorough study of the degradation effect on the products, more resistant materials can be found which are able to withstand these adversities and increase the lifespan of wood in regular contact with chemical agents. This is achievable by the determination of the cost-effectiveness of the substitute material to replace these components with alternative ones, with properties that better resist the deterioration effects promoted by aggressive environments. No studies have been found so far strictly focused on this matter. The objective of this study is to evaluate the degradation presented by two types of wood, beech and oak, which are exposed to the action of chlorine in municipal facilities. This degradation varies according to the chlorine content and the materials’ time of contact with the chemical agent, allowing the selection of new materials which will provide an extended lifetime of the components, reducing maintenance drastically, as well as costs for the facilities and the risk to public health. The performed experimental tests have shown that the oak wood has the best results regarding chlorine degradation resistance.

An experimental study and modeling of the behavior of wood during compression along the fibers was carried out. The nonlinear analytical dependence of the load on the strain was considered. Attention was focused on the post-peak stage of deformation in order to determine the load and displacement at which the transition to the stage of plastic deformation occurs. The work was aimed at substantiating the application of the energy criterion of brittle fracture as a criterion for the transition to the stage of plastic deformation. To achieve this goal, methods of mathematical modeling and analysis of test results were used. As an upshot, a simple and practical procedure was developed to predict the transition point to the above stage of plastic deformation. The simulation results were consistent with laboratory tests of samples and fragments of structures. The practical significance of this criterion lies in its possible use as an additional tool for analyzing the condition of some wooden structures. Energy criteria, including the one mentioned above, belong to fairly universal criteria. Accordingly, the research methodology can be adapted to analyze the behavior of, for example, composites under other types of loads in further studies.

Nowadays environmental requirements keep on increasing, specifically more related to waste produced from production. Manufacturing companies should take measures in recycling or use their materials for secondary purpose. Furthermore, well known recycling here and later methods exists for standard materials like wood and thermoplastic polymers. This is not the case for thermoset polymers, which are used extensively, especially in the footwear industry. At present the most widely used method of disposal of the thermosets polymers are landfills and incineration, which results in high air, land, and water pollution. These pollutions greatly affect the environment. The aim of the project is to obtain a new waste based composite material sheets for the footwear production applications that can replace traditional insole materials. This obtained material should be cost effective in comparision to the existing material. Ethylene vinyl acetate copolymer. beech wood waste generated in the manufacturing of footwear were used for the fabrication of the composite. Lamination design of three-layered composite was also studied to investigate the effects of the layer thickness and waste content and binder on the structure, water absorption and mechanical properties of the composites. Composites were prepared using two kinds of binding materials polyamide and expanded polystyrene. It was found that the waste obtained from the manufacturing of shoe parts such as last and insole milling can be used to produce composite sheet with good physical and mechanical properties, i.e. similar or better to the existing insole materials, such as carboard or cork. The mechanical properties of three-layered composite decreased with increasing beech wood content. Composites containing binder materials have significantly higher values of strength and resistance of the flexing in comparision to composites without binders. As a final part of this project, impact of the use of production waste on the cost of composite raw materials was determined., Šiais laikais aplinkosaugos reikalavimai nuolat auga, ypač susiję su gamybos atliekomis. Gamybos įmonės turėtų imtis priemonių perdirbdamos šias medžiagas arba naudoti šias medžiagas antrinei paskirčiai. Yra gerai žinomi standartinių medžiagų, tokių kaip mediena ir termoplastiniai polimerai, perdirbimo metodai. Tai netaikoma termoreaktingiems polimerams, kurie plačiai naudojami, ypač avalynės pramonėje. Šiuo metu plačiausiai naudojamas termoreaktingų polimerų šalinimo būdas yra sąvartynai ir deginimas, todėl labai teršiama oras, žemė ir vanduo. Ši tarša labai veikia aplinką. Projekto tikslas – gauti naujus atliekų pagrindu pagamintus kompozitinių medžiagų lakštus, skirtus avalynės gamybai, galinčius pakeisti tradicines vidpadžių medžiagas. Gautas kompozitas turėtų būti ekonomiškai efektyvus, palyginti su šiuo metu naudojamomis medžiagomis. Darbe kompozito gamybai panaudotas etileno vinilacetato kopolimeras ir buko medienos atliekos, susidarančios gaminant avalynę. Taip pat buvo tiriamas trijų sluoksnių kompozito laminato gavimo galimybė, siekiant ištirti sluoksnio storio, atliekų kiekio ir rišiklio įtaką kompozitų lenkimo ir stiprumo savybėms. Kompozitai buvo ruošiami naudojant dviejų rūšių rišamąsias medžiagas - poliamidą ir putų polistireną. Nustatyta, kad atliekos, gautos gaminant avalynės detales, tokias kaip kurpalis ir vidpadis frezavimo būdu, gali būti panaudotos geromis fizinėmis ir mechaninėmis savybėmis pasižyminčio kompozitinio laminato gamybai. Nustatyta, kad trisluoksnio kompozito laminato mechaninės savybės padidėjo didėjant buko medienos kiekiui. Kompozitai, kurių sudėtyje yra rišamųjų medžiagų, pasižymi žymiai didesnėmis stiprumo ir atsparumo lenkimui vertėmis, palyginti su kompozitais be rišamųjų medžiagų. Baigiamojoje šio projekto dalyje nustatytas gamybos atliekų panaudojimo poveikis žaliavų kompozitams savikainai.

Wood-polymer composites are increasingly produced through fused deposition modeling (FDM)—an additive manufacturing technique. The versatility of this technology has attracted several industries to print complex shapes and structures. This underscores the importance of studying the mechanical properties of the FDM parts, specifically, their elastic properties. A numerical homogenization methodology is introduced in the present study, focusing on the fundamental aspect of the elastic properties. Investigations were carried out on the influence of various parameters like wood volume fraction, aspect ratio, and internal porosity. The numerical results were validated using analytical models and experimental data. The comparison showed a satisfactory agreement with experimental data, where the relative error did not exceed 10%, leading to a strong conclusion about the validity and effectiveness of the proposed approach.

The high demand for wood-based composites generates a greater use of wood adhesives. The current industrial challenge is to develop modified synthetic adhesives to remove harmful formaldehyde, and to test natural adhesives. The scope of the current research included the manufacturing of high-density fiberboards (HDF) using natural binders such as polylactic acid (PLA), polycaprolactone (PCL), and thermoplastic starch (TPS) with different resination (12%, 15%, 20%). The HDF with biopolymers was compared to a reference HDF, manufactured following the example of industrial technology, with commonly used adhesives such as urea-formaldehyde (UF) resin. Different mechanical and physical properties were determined, namely modulus of rupture (MOR), modulus of elasticity (MOE), internal bonding strength (IB), thickness swelling (TS), water absorption (WA), surface water absorption (SWA), contact angle, as well as density profile; scanning electron microscope (SEM) analysis was also performed. The results showed that increasing the binder content significantly improved the mechanical properties of the panels in the case of starch binder (MOR from 31.35 N mm−2 to 40.10 N mm−2, IB from 0.24 N mm−2 to 0.39 N mm−2 for dry starch), and reduces these in the case of PLA and PCL. The wet method of starch addition improved the mechanical properties of panels; however, it negatively influenced the reaction of the panels to water (WA 90.3% for dry starch and 105.9% for wet starch after 24 h soaking). Due to dynamically evaporating solvents from the PLA and PCL binding mixtures, a development of the fibers’ resination (blending) techniques should be performed, to avoid the uneven spreading of the binder over the resinated material.

Extended Reality (XR) is a term that refers to virtual, augmented, and, more recently, mixed reality (VR/AR//MR), which are key enabling technologies of the Industry 4.0 (I4.0) and the simulated digital environment of the metaverse. XR enables the simulation of workplace scenarios, providing workers with training in a risk-free environment, resulting in cost savings, improved occupational risk prevention, and enhanced decision-making processes. XR is ideal for supporting digital transformation for organisations in fields such as production, occupational risk prevention, maintenance, and marketing. XR is also a key driver for training initiatives aimed at promoting good practices in the circular economy in specific sectors such as woodworking and furniture (W&F). The European Commission has recognised the potential of XR for the W&F sector, funding initiatives such as the European project, Allview, which seeks to identify the most appropriate and beneficial technologies of I4.0 with a green and digital transition focus from the perspective of vocational education and training (VET). This paper presents the work carried out within the framework of Allview, including the research and comparison of current software and hardware of XR tools suitable for VET in the W&F field, a review of successful examples of XR applied to W&F training actions, and an analysis of the opinions gathered from European students, teachers, and training organisations regarding the use of XR in education. As a result, the authors present a training pathway aimed at the development and implementation of a XR training scenario/lab/environment focused on VR, 360° videos, and MR, as a guideline for developing immersive XR training contents, contributing to the digital and green transformation of VET in the W&F sector.

Leaves are the most important photosynthetic organs in most woody plants, but chloroplasts are also found in organs optimized for other functions. However, the actual photosynthetic efficiency of these chloroplasts is still unclear. We analyzed bark and wood chloroplasts of Fraxinus ornus L. saplings. Optical and spectroscopic methods were applied to stem samples and compared with leaves. A sharp light gradient was detected along the stem radial direction, with blue light mainly absorbed by the outer bark, and far-red-enriched light reaching the underlying xylem and pith. Chlorophylls were evident in the xylem rays and the pith and showed an increasing concentration gradient toward the bark. The stem photosynthetic apparatus showed features typical of acclimation to a low-light environment, such as larger grana stacks, lower chlorophyll a/b and photosystem I/II ratios compared with leaves. Despite likely receiving very few photons, wood chloroplasts were photosynthetically active and fully capable of generating a light-dependent electron transport. Our data provide a comprehensive scenario of the functional features of bark and wood chloroplasts in a woody species and suggest that stem photosynthesis is coherently optimized to the prevailing micro-environmental conditions at the bark and wood level.